Quite commonly particulate material such as asbestos, cement, grain, sand or the like is transported or stored in a hopper having an inwardly tapered lower end portion that terminates in a lower discharge opening. These hoppers can be, for example, stationary structures at a storage location, or part of the structure of a railroad freight car. Quite often there is a tendency for the material to adhere together or to "cake" above the discharge outlet, thus preventing further discharge of the material from the hopper.
One common method for remedying this problem is for a workman simply to pound on the side of the hopper, e.g., with a sledge hammer or some other blunt object to jar the caked material loose. Another method is simply to use a rod or other object to probe into the caked material to knock it loose. There have in the past been various proposals to employ mechanical devices to alleviate this problem, such as moving members to continually agitate and stir the material to prevent compaction, or flexible tubes which are attached to a fluid source, such as air, so that the tubes randomly whip about the inside of the container to continually agitate the material. However, to the best knowledge of the applicant, such mechanical devices have not been widely accepted commercially, so that the common remedy remains the impacting of the sides of the hopper or using manually operated rods or poles to jar the material loose. A search of the patent literature has disclosed a number of concepts utilizing a pressurized fluid medium to effect the loosening of the caked material in a hopper. These are as follows: In U.S. Pat. No. 2,025,404 --Stahn, there is disclosed apparatus for dispelling sand which has stuck to the walls of a container, the apparatus includes a flexible tube vertically suspended inside the container wherein compressed air is supplied to the tube to cause it to move in a whip-like manner. In addition, in U.S. Pat. No. 2,115,023--Kennedy, et al, there is disclosed means for handling pulverulent, granular like materials, including a container for the materials and a flexible tubular member vertically suspended within the container in communication with an air source which causes the flexible hose to move in a whip like manner to dislodge material adhering to the container.
A fluidly propelled tubular flexible member has also been used to stir the contents inside a container such as in U.S. Pat. No. 2,501,047 --Gustafson, et al, where there is disclosed a dry powder sprayer, including a flexible tube vertically suspended inside a container containing therein a powder mass; a flexible tube in communication with an air source causes the tube to flap around in the container to nebulate and aerate the powder mass.
Frequently these tubular members are permanently mounted to the container utilizing a variety of mounting and sealing methods. In U.S. Pat. No. 3,942,689--Dakin, Jr., et al, there is disclosed a vertical guide member permanently supporting a flexible tubing slideably engaged within the guide member to permit varying the elevation of the guide member relative to the tube. The slideably engaged tubing allowed the exposed length of the tube to be varied in order to dislodge compacted materials from increasing heights within the container. A mechanical seal or stuffing box provided a seal between the guide member and the container.
In order to provide additional area coverage within the container, additional tubular members are often spaced about the inside of the container and connected to a common manifold. In. U.S. Pat. No. 3,777,912--Deeks, there is disclosed an apparatus for removing material from hopper-type railroad tank cars wherein rubber hoses are suspended over each hopper symmetrically about the transverse centerline and on the longitudinal centerline. The top ends of the hoses are fixed to air supply pipes which are held rigid by structural supports.
A plurality of flexible tubing members are also utilized for mixing the contents of a container such as in U.S. Pat. No. 2,988,286--Snyder, et al, wherein there is disclosed a plurality of flexible hoses suspended from a pipe across the inside of a liquid container, the hoses are connected to a liquid source which when activated causes liquid to flow through the hoses into the container causing the hoses to move in a whip-like manner to stir the contents of the container.
A plurality of flexible tubular hoses has also been used as cleaning apparatus such as in U.S. Pat. No. 3,799,444--Reed, wherein there is disclosed an apparatus for removing material from a workpiece, the apparatus comprising a plurality of flexible rubber tubes supplied with compressed air through a manifold mounted longitudinally across the inside of a cleaning container. The manifold is mechanically moved laterally across the inside of the container in a direction perpendicular to the longitudinal axis of the cross beam so that the rubber tubes are whipped against the entire surface of the workpiece.
Other apparatus for assisting the discharge of compacted cargo materials include U.S. Pat. No. 3,337,094--Houston, wherein there is disclosed a grain storage container including a plurality of fluid-type tubes therein which when filled with fluid occupy a larger volume which produces forces in a generally horizontal direction throughout the material to dislodge the material from the container. In U.S. Pat. No. 3,933,280--Plumb, there is disclosed a bulk cargo unloader aerator including an insertable and removeable aerating assembly comprising a rigid tube having a plurality of holes therein and covered by a porous fabric sleeve which is caused to pulsate due to fluctuations in an air supply such that the pulsating fabric impacts material in a storage hopper. The hopper includes a laterally projecting neck which is provided with a coupling arrangement to mate with the aerating assembly.
In U.S. Pat. No. 3,833,151--Lieckfeld, there is disclosed apparatus for assisting the discharge of particulate solids from a bin wherein a hollow body is attached to the bottom of the bin and caused to expand and contract by the action of a counter weight attached to the top of the hollow body and suspended outside the bin.
In U.S. Pat. No. 3,237,389--Green, there is disclosed a fruit picking apparatus utilizing a plurality of flexible tubular members mounted on a boom for conducting pressurized fluid which imparts to the tube a whip-like movement to dislodge fruit from a tree.
It should be appreciated that a number of apparatus and methods have been utilized to assist in the discharge of compacted material from storage containers. Typically a plurality of these devices are disposed at selected locations throughout the container to provide adequate dislodging of materials from all portions of the container. A large container requires an increased number of dislodging devices, as well as an increase in the fluid energy to drive the dislodging devices. Typically these dislodging devices are connected to a common manifold thereby making it difficult to concentrate the fluid energy to one particular dislodging device located proximate to a selected part of the container.